Katsoulis Joannis, Wälchli Julia, Kobel Simone, Gholami Hadi, Mericske-Stern Regina
Department of Prosthodontics, School of Dental Medicine, University of Bern, Bern, Switzerland.
Clin Implant Dent Relat Res. 2015 Jan;17 Suppl 1:e75-85. doi: 10.1111/cid.12130. Epub 2013 Aug 5.
Implant-overdentures supported by rigid bars provide stability in the edentulous atrophic mandible. However, fractures of solder joints and matrices, and loosening of screws and matrices were observed with soldered gold bars (G-bars). Computer-aided designed/computer-assisted manufactured (CAD/CAM) titanium bars (Ti-bars) may reduce technical complications due to enhanced material quality.
To compare prosthetic-technical maintenance service of mandibular implant-overdentures supported by CAD/CAM Ti-bar and soldered G-bar.
Edentulous patients were consecutively admitted for implant-prosthodontic treatment with a maxillary complete denture and a mandibular implant-overdenture connected to a rigid G-bar or Ti-bar. Maintenance service and problems with the implant-retention device complex and the prosthesis were recorded during minimally 3-4 years. Annual peri-implant crestal bone level changes (ΔBIC) were radiographically assessed.
Data of 213 edentulous patients (mean age 68 ± 10 years), who had received a total of 477 tapered implants, were available. Ti-bar and G-bar comprised 101 and 112 patients with 231 and 246 implants, respectively. Ti-bar mostly exhibited distal bar extensions (96%) compared to 34% of G-bar (p < .001). Fracture rate of bars extensions (4.7% vs 14.8%, p < .001) and matrices (1% vs 13%, p < .001) was lower for Ti-bar. Matrices activation was required 2.4× less often in Ti-bar. ΔBIC remained stable for both groups.
Implant overdentures supported by soldered gold bars or milled CAD/CAM Ti-bars are a successful treatment modality but require regular maintenance service. These short-term observations support the hypothesis that CAD/CAM Ti-bars reduce technical complications. Fracture location indicated that the titanium thickness around the screw-access hole should be increased.
由刚性杆支持的种植覆盖义齿可为无牙萎缩下颌骨提供稳定性。然而，使用焊接金条（G型杆）时，观察到焊点和基体骨折以及螺钉和基体松动。计算机辅助设计/计算机辅助制造（CAD/CAM）钛杆（Ti型杆）由于材料质量提高，可能会减少技术并发症。
比较由CAD/CAM Ti型杆和焊接G型杆支持的下颌种植覆盖义齿的修复技术维护服务。
连续收治无牙患者，进行种植修复治疗，上颌全口义齿，下颌种植覆盖义齿连接刚性G型杆或Ti型杆。在至少3 - 4年的时间里记录种植体固位装置复合体和义齿的维护服务及问题。每年通过影像学评估种植体周围嵴顶骨水平变化（ΔBIC）。
有213例无牙患者（平均年龄68±10岁）的数据，共植入477颗锥形种植体。Ti型杆组和G型杆组分别有101例和112例患者，植入231颗和246颗种植体。与G型杆的34%相比，Ti型杆大多表现为杆的远端延伸（96%）（p <.001）。Ti型杆的杆延伸骨折率（4.7%对14.8%，p <.001）和基体骨折率（1%对13%，p <.001）较低。Ti型杆中基体激活的频率低2.4倍。两组的ΔBIC均保持稳定。
由焊接金条或铣削CAD/CAM Ti型杆支持的种植覆盖义齿是一种成功的治疗方式，但需要定期维护服务。这些短期观察结果支持CAD/CAM Ti型杆减少技术并发症的假设。骨折位置表明，应增加螺钉接入孔周围的钛厚度。
